libESMTP is an SMTP client that manages posting (or submission of) electronic mail via a preconfigured MTA.

It may be used as part of a MUA, or other program that must be able to post electronic mail where mail functionality may not be that program's primary purpose.

libESMTP's high-level API shields developers from the complexity of SMTP. It transparently handles many SMTP extensions including authentication, TLS, and PIPELINING for performance. Even without a pipelining server, libESMTP offers much better performance than would be expected from a simple client.

The sendgmail command provides a minimal sendmail-compatible front-end that connects to Gmail using OAuth2. It is specifically designed for use with git send-email. The command needs a Gmail API key to function.

Guix's version of sendgmail has been patched for compatibility with all known forks, including support for non-@gmail.com email addresses.

aerc is a textual email client for terminals. It features:

1. First-class support for using patches and git send-email

2. Vi-like keybindings and command system

3. A built-in console

4. Support for multiple accounts

This Python module can be used to generate and parse RFC 5451/7001/7601 Authentication-Results email headers. It supports extensions such as:

• RFC 5617 DKIM/ADSP

• RFC 6008 DKIM signature identification (header.b)

• RFC 6212 VBR

• RFC 6577 SPF

• RFC 7281 Authentication-Results registration for S/MIME

• RFC 7293 The Require-Recipient-Valid-Since header field

• RFC 7489 DMARC

• ARC (draft-ietf-dmarc-arc-protocol-08)

Abook is a text-based address book program designed to use with the Mutt mail client.

This package provides an Emacs-based interface to the Notmuch mail system.

Mail::SPF is the Sender Policy Framework implemented in Perl.

The filter-rspamd OpenSMTPd filter implements the Rspamd protocol and allows OpenSMTPd to request an Rspamd analysis of an SMTP transaction before a message is committed to queue.

Alpine is a text-based mail and news client. Alpine includes several tools and applications:

1. alpine, the Alpine mailer

2. pico, the standalone text editor, GNU nano's predecessor

3. pilot, the standalone file system navigator

This module wraps MIME::Base64 and MIME::QuotedPrint.

The purpose of this mail library is to provide a portable, efficient framework for different kinds of mail access: IMAP, SMTP, POP and NNTP. It provides an API for C language. It's the low-level API used by MailCore and MailCore 2.

This package provides a tool to extract, recover and undelete email messages from Outlook Express .dbx files.

Mumi is a Debbugs web interface.

Headers of the Linux-Libre kernel.

GNU Binutils is a collection of tools for working with binary files. Perhaps the most notable are "ld", a linker, and "as", an assembler. Other tools include programs to display binary profiling information, list the strings in a binary file, and utilities for working with archives. The "bfd" library for working with executable and object formats is also included.

Binaries used to bootstrap the distribution.

Guile is the GNU Ubiquitous Intelligent Language for Extensions, the official extension language of the GNU system. It is an implementation of the Scheme language which can be easily embedded in other applications to provide a convenient means of extending the functionality of the application without requiring the source code to be rewritten.

Tarballs containing all the bootstrap binaries

Guile is the GNU Ubiquitous Intelligent Language for Extensions, the official extension language of the GNU system. It is an implementation of the Scheme language which can be easily embedded in other applications to provide a convenient means of extending the functionality of the application without requiring the source code to be rewritten.

Guile is the GNU Ubiquitous Intelligent Language for Extensions, the official extension language of the GNU system. It is an implementation of the Scheme language which can be easily embedded in other applications to provide a convenient means of extending the functionality of the application without requiring the source code to be rewritten.

mandoc is a suite of tools compiling mdoc, the roff macro language of choice for BSD manual pages, and man, the predominant historical language for UNIX manuals. It is small and quite fast. The main component of the toolset is the mandoc utility program, based on the libmandoc validating compiler, to format output for UTF-8 and ASCII UNIX terminals, HTML 5, PostScript, and PDF. Additional tools include the man viewer, and apropos and whatis.

XMLtoMan and XMLMantoHTML are two small scripts to convert xml to man pages in groff format or html. It features the usual man page items such as description, options, see also, etc.

Man-db is an implementation of the standard Unix documentation system accessed using the man command. It uses a Berkeley DB database in place of the traditional flat-text whatis databases.

Txt2man converts flat ASCII text to man page format.